Axle thread and bearing protector

ABSTRACT

An axle thread protection system which simultaneously protects the skateboard wheel bearings from dust and debris. A plastic shield is used between the hanger of the skateboard truck and the skateboard wheel. The shield generally held adjacent to the exposed outer surface of the inner skateboard wheel bearing. A capping nut having a similar bearing-protector flange has a nut section coupled to a cage section that holds in place a locking ring and thread protector. The locking ring helps to reduce vibration and keep the capping nut on the threaded end of the skateboard axle while a thread protector reduces injury to the threaded axle end of the skateboard.

COPYRIGHT AUTHORIZATION

Portions of the disclosure of this patent document may contain material which is subject to copyright and/or mask work protection. The copyright and/or mask work owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright and/or mask work rights whatsoever.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to skateboards and more particularly to a thread protector for the threads on the axles of skateboards.

2. Description of the Related Art

Skateboards are generally well known in the art. A board of approximately two feet has four wheels attached in two pairs at opposite ends or generally adjacent thereto of the board. One can propel oneself down a hill or along a flat surface by keeping one foot on the board and pushing off on the ground on the other.

In recent history, skateboards have become a means by which tricks and acrobatics can be performed as is documented in two recent films “Lords of Dogtown” (2005) and “Dogtown and Z-boys” (2001).

As is portrayed/documented in these movies, skateboarding rose collaterally from the beach life and surfing environment in and around Venice, Calif. during the 1980s. Particularly during a drought in Southern California, swimming pools dried out (or were emptied) to become the first skate parks for skateboarders. The smooth vertical sides of a swimming pool lent it to skateboarding and the change in direction enjoyed at the top of the skateboarder's arc became an opportunity to perform tricks and acrobatics.

The sides of canyons and slopes in Southern California, particularly those of empty schoolyards became available skating parks for skateboarders. Obstacles such as small rails, benches, and the like became objects against which the skateboarders could “grind” by causing their boards to jump up into the air and engage a corner or other surface with the bottom of the skateboard and slide along the surface until the skateboard generally dropped off due to the force of gravity.

This “grinding” creates a lot of stress on the truck (the wheel-bearing portion of the skateboard) against which grinding occurs. The bottom of the board away from the wheels, and consequently away from the trucks, can also be used for grinding.

The present inventor is known for his development in skateboard technology. His personal experience with riding, the conditions of riding, the community in Southern California that gave rise to prior and current skateboard cultures have given him insight and knowledge of the drawbacks and needed advancement in the arts of skateboarding equipment.

The following patents invented by the inventor of the technology set forth herein are incorporated by this reference and include:

U.S. Pat. No. 4,898,398 issued to Cassel on Feb. 6, 1990 for a High Performance Grinding King Pin And Associated Apparatus;

U.S. Pat. No. D412,833 issued to Cassel on Aug. 17, 1999 for a Hex Nut Holding Washer; and

U.S. Pat. No. 6,394,723 issued to Cassel on May 28, 2002 for a Fastener With Substrate-Engaging Portions.

Additionally, the instant inventor has also invented a novel design for snowboards, snowboarding, a sport generally considered to be an extension of surfing and skateboarding. U.S. Pat. No. D418,545 issued to Cassel on Jan. 4, 2000 for a High Strength Snowboard is incorporated herein by this reference thereto.

With any skateboarding activity, the continued rolling of wheels is very important as when the wheels lock up, the rider is thrown from the board and can often be injured, especially if the board traveling at a high rate of speed. Additionally, due to the delicate balance involved, any unexpected behavior of the skateboard has the tendency to detract from the skateboarding experience and can lead to injury.

Debris such as grit, sand, dirt, and dust are generally prevented from entering the bearings of the wheels by the sealing of the bearings. However, some bearings are not sealed, or such sealed bearings may be incompletely sealed, and it becomes necessary or advantageous to include a cover or shield for the bearings of the skateboard wheels. The inventor's prior technology, known in the trade as RIMS™ and generally marketed under the trademark of GRINDKING® are known in the art. The RIMS™ system helps protect the bearings of the wheels and the RIMS™ system is shown as prior art in FIGS. 2 and 4. While the RIMS™ system is highly effective and has enjoyed considerable success in the marketplace, it does not protect the axle threads of the skateboard axle. Consequently the art is lacking as the scarring and abrasion of the axle threads generally had a tendency to affect performance and make it more difficult to change wheels and the like as the damaged threads and accompanying thread grooves have to be recut or otherwise restored in order to allow the unfitting and refitting of the associated nut that holds the wheel on the axle.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of bearing protection systems for skateboard wheel bearings now present in the prior art, the present invention provides new technology by which not only can the bearings of the skateboard wheel be protected, but the vulnerable threads of the skateboard axle can also better withstand the rigors of skateboarding without injury or with at least diminished injury or risk thereof.

The general purpose of the present invention, which will be described subsequently in greater detail, is to provide an integrated bearing and axle thread protection means which has many advantages of prior bearing protection systems heretofore and many novel features that result a new skateboard truck and wheel protection system which is not anticipated, rendered obvious, suggested, taught, or even implied by any of the prior art skateboard wheel bearing protection systems or other skateboard axle thread protecting systems, either alone or in any combination thereof.

In association with known skateboard wheel bearing protection technology, a cap, which may be hemispherical, is used to protect the end of the axle and in combination prevents debris such as grit, dirt, sand, dust, and other small particles from engaging the skateboard wheel bearings while simultaneously preventing injury to the threaded end of the skateboard axle.

A nut-like device having a generally orthogonal, or generally perpendicular, and co-axial flange at its base has an upper cage section which entraps a locking nut of nylon or similar material in conjunction with a hemispherical or other-shaped cap. The flange at the base of the nut section provides mechanical protection for the exposed bearing of the skateboard wheel which can suffer damage from debris and grit as well as from tools that dent or damage the generally soft metal case bearing. The nut section provides threaded engagement with the axle and substantial mechanical and stability for the axle thread protected for skateboard set forth herein. The locking section prevents slippage between the axle thread protector and the threaded axle while the cap resiliently protects against damage and injury to the threaded skateboard axle end.

Ornamental surface marking may be present along the flange or otherwise and a plastic shield may provide a barrier to debris for the inner bearing of the skateboard wheel and is generally located between a shoulder of an axle and the exposed inner bearing surface or otherwise disposed such as to protect that exposed inner bearing surface.

In one embodiment, a protector for skateboard axle threads has a nut section with a top, a bottom, and a central axis. The nut section is adapted to threadably engage an axle of a skateboard and has a flange coupled to the nut section adjacent the bottom of the nut section. The flange extends outwardly from the bottom in a direction generally perpendicular, or orthogonal, to the central axis. The flange is sized and adapted to cover and protect an adjacent skateboard wheel bearing from debris such as dirt, sand, grit, etc.

A locking ring is coupled to the nut section and a metal cap is coupled to the locking ring. The two are coupled in such a way that a threaded axle of a skateboard truck is protected from abrasion by the metal cap and a bearing of wheel upon the threaded axle is protected from debris by the flange as set forth, above.

In another embodiment of the present invention, a skateboard truck has a threaded axle and a skateboard wheel with a first bearing rotating upon the threaded axle. A nut section having a top, a bottom, and a central axis is provided for protecting the threaded skateboard axle. The nut section is adapted to threadably engage the threaded axle and has a flange coupled to the nut section adjacent the bottom. The flange extends outwardly from the bottom in a direction generally perpendicular to the central axis. The flange is sized and adapted to cover and protect the first bearing.

A locking ring is coupled to the nut section and a metal cap is coupled to the locking ring such that the threaded axle of a skateboard truck is protected from abrasion by the metal cap and the first bearing of the skateboard wheel is protected from debris by the flange.

OBJECTS OF THE INVENTION

Many objects and goals are present within the specification and disclosure set forth herein. Below is a partial list of such objects of the present invention but by no means should it be considered absolutely complete.

It is an object of the present invention to provide protection for skateboard axle threads by simultaneously protecting exposed skateboard wheel bearing surfaces.

It is yet another object of the present invention to provide axle thread protection to skateboards in a manner that is simple to use, easy to understand, and readily manufacturable.

It is another object of the present invention to provide integrated protection for skateboard wheel bearings and their exposed surfaces while simultaneously providing protection for skateboard axle threads.

These and other objects and advantages of the present invention will be apparent from a review of the following specification and accompanying drawings. The foregoing objects are some of but a few of the goals sought to be attained by the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of axle thread protection system set forth herein showing the skateboard truck as it would appear when the skateboard is upside down and the viewer facing the inside of the board towards an end.

FIG. 2 is an exploded view of the inventor's prior art system which does not provide axle thread protection.

FIG. 3 is a cross sectional view of the axle thread of protection system of FIG. 1 when assembled.

FIG. 4 is a side cross sectional view of a prior art system view shown in FIG. 2 when assembled.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The detailed description set forth below in connection with the appended drawings is intended as a description of presently-preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed and/or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

Referring to the drawings where like numerals of reference designate like elements throughout it will be noted a skateboard truck 100 has a base plate 102 (which is attached to a skateboard via the mounting holes 104) and a hanger 106 which is pivotably coupled to the base plate 102 via the pivot 108 and kingpin 110. The kingpin 110 has proximal 120 and distal 122 bushings which lie on either side of a coupling portion of the hanger 106. The bushings 120, 122 are generally elastic in nature and enable the protrusion 124 of the hanger 106 to articulate in the pivot depression 126 of the pivot 108. The foregoing is generally well known in the art for at least the past several years.

The hanger 106 has oppositely opposed axles 130 of which only one is shown in FIG. 1. The axle 130 may have a shoulder 132 followed by distal threads 134 and an optional narrower protrusion 136.

The axle 130 provides a spindle for the wheel 140 which is generally held onto the axle 130 by a plain or regular nut or the like (not shown). However, in the present invention, a special capping nut 150 is used in connection with a shield 152 of plastic or other material. The capping nut serves to protect both the outer bearings of the wheel 140 as well as protect for the threads 134 of the axle 130. The plastic shield 152 provides protection for the inner bearings 162 of the wheel 140. This is shown in more detail in FIG. 3. FIGS. 2 and 4 show the prior art RIMS™ system as mentioned in the background section, above. Like numerals of reference are used to refer to similar elements.

As shown in FIG. 3, the wheel 140 generally has a wide central opening 170 which allows the outer edge 172 of the wheel to flex in response to stress and pressure that often occurs during the turning of the skateboard. The axle 130 travels through central openings of the inner bearing 162 with its ball bearings 176 as well as the outer bearing 160 with its ball bearings 176. The inner and outer bearings 162, 160 are generally fit by friction or otherwise within the center of the wheel 140.

In practice, the shield 152 is made of plastic or other resilient material. The shield 152 is threaded upon or is otherwise carried by the axle 130 and its travel toward the hanger 106 is stopped by the axle shoulder 132 or otherwise. The wheel 140 is then placed on the axle 132 and the capping nut 150 is threaded onto the axle threads 134.

The capping nut 150 has (with respect to FIG. 3) a lower threaded nut section which is circumscribed generally at its base by a flange 182 that is generally orthogonal, or perpendicular, to an imaginary axis running through the center of the generally circular threaded nut section 180. At generally the top and at the outer perimeter of the lower threaded nut section 180 is a circular wall 184 terminating in a bendable or otherwise workable restraint 186. In combination, the circular wall 184 with its crowning restraint 186 serve as a cage section generally referred to by reference number 188. The cage section 188 serves as a partial housing for a locking ring 190 as well as the thread protector 192 with its circumscribing flange 194. The thread protector 192 may have a hemispherical or other protruding or otherwise dome 196 which is circumscribed by the flange 194. The restraint 186 crimpingly or otherwise in a compressing or restraining manner holds the circumscribing flange 194 of the thread protector 192 atop the locking ring 190. Other means known in the art may be used to couple the thread protector 192 to the locking ring 190 or otherwise. The locking ring 190 may then held in compression between the thread projector 192 and the lower threaded nut section 180. These components may be made in an integrated fashion. However, the locking ring 190 is generally made of nylon or other soft material and is generally not threaded as such threads are cut into the material of the locking ring 190 when the capping nut 150 is threaded upon the threads 134 of the axle 130. The locking ring serves to retain the capping nut on the axle by, among other things, absorbing shock and preventing vibration in the capping nut 150.

FIG. 3 can be contrasted visually with FIG. 4 where no capping nut is involved and no caged section is involved. No caged section accommodating the thread protector is present in FIG. 4. By providing the thread protector 192, the bearing protection system set forth herein and shown in FIGS. 2 and 4 is additionally enhanced in a manner that provides a better skateboard experience and better operation of the skateboard. The axle thread and bearing protection system set forth herein not only protects axle threads 134 but allows the bearings 160, 162 to stay cleaner and to last longer as well as guarding against tool damage when repair is attempted on broken, damaged, marred, or otherwise injured skateboard axle threads 134. The flange 182 at the base of the nut section 180 provides mechanical protection for the exposed bearing 160 of the skateboard wheel 140 which can suffer damage from debris and grit as well as from tools that dent or damage the generally soft metal case bearing. Such debris is repelled by the flange 182 and the durable nature of the flange 182 absorbs the shock that can occur when a socket wrench or other tool slips and forcefully collides with what would otherwise be the soft track housing or case material for the bearing. When dented or injured, the track case can interfere with the free rolling of the encased bearings. Additionally, clean bearings roll faster and in conjunction with the protection provided by the capping nut 150 with its thread protector 192, the protected parts of the skateboard wheel, its bearings, and the skateboard truck 100 last longer, operate better, and aid in reducing equipment failure and personal injury to the rider.

Generally, the dome 196 of the thread protector 192 is made of high-abrasion resistant material and may have an inner dome diameter of 0.240 inches and outer flange diameter 194 of 0.425 inches. The height of the thread protector 192 may be approximately 0.200 inches with the dome protrusion 196 having an outer radius of approximately 0.170 inches. The radius of curvature for the transition between the dome portion 196 and flange 194 may be approximately 0.025 inches. The height of the thread protector flange 194 may be approximately 0.050 inches.

For the lower threaded nut section 180, the hex nut shape of one embodiment may be approximately 0.560 inches between oppositely opposed points while the distance between oppositely opposed flat surfaces may be approximately 0.495 inches. The inner diameter of the nut section 180 may be approximately 0.350 inches with the outer diameter of the circular wall 184 being approximately 0.485 inches.

The inner diameter of the circular wall section 184 may be approximately 0.435 inches with the locking ring 190 having an inner diameter of approximately 0.267 inches and an outer diameter of approximately 0.425 inches. A wide variety of useful materials may be used to construct the locking ring 190. However, nylon is one substance which may be preferred under most circumstances. The height of the restraint 186 as shown FIG. 3 may be approximately 0.125 inches with its width being approximately 0.040 inches at the base. A radius of curvature of approximately 0.050 inches may be seen at the curved upper portion of the restraint 186 where it crimps the flange 194 of the thread protector 192. The height between the top of flange 182 of the lower threaded nut section 180 and the transition from the circular wall 184 of the restraint 186 may be approximately 0.265 inches with the distance between the transition and the seat for the locking ring 190 created by the lower threaded nut section 180 of being approximately 0.190 inches. A distance between the bottom of the capping nut 150 and the locking ring seat may be approximately 0.150 inches. The flange 182 of the lower threaded nut section 180 may be approximately 0.025 inches thick while the distance between the bottom of the capping nut 150 and the bottom of that flange 182 may also be approximately 0.025 inches. The outer diameter of the base of the capping nut 150 may be approximately 0.410 inches and the overall height of the capping nut 150 may be approximately 0.540 inches.

The axle 130 at its threads 134 may be approximately 5/16 inches in diameter with the flange 182 of sufficient diameter to cover and protect the bearing 160 without interfering with the operations of the wheel 140. Similarly, the shield 152 may be approximately sized to protect the inner bearing 162.

While the specific indication of sizes and distances set forth herein indicate one embodiment of the present invention, variations may exist that go beyond these specifications either relatively or unilaterally with respect to individual ones of such distances and specifications.

While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concept. With regards to particular embodiments, it is recognized that additional variations to the present invention may be devised without departing from the inventive concept. 

1. A protector for axle threads on a skateboard and a bearing of a wheel on the threaded skateboard axle, comprising: a nut section having a top, a bottom, and a central axis, said nut section adapted to threadably engage the axle of the skateboard; a flange coupled to said nut section adjacent said bottom, said flange extending outwardly from said bottom in a direction generally perpendicular to said central axis, said flange sized and adapted to cover and protect the adjacent skateboard wheel bearing; a locking ring coupled to said nut section; and a metal cap coupled to said locking ring; whereby the threaded axle of a skateboard truck is protected from abrasion by said metal cap and the bearing of the wheel upon the threaded axle is protected from debris and damage by said flange.
 2. A protector for axle threads on a skateboard and a bearing of a wheel on the threaded skateboard axle as set forth in claim 1, further comprising: a cage section coupled to said top of said nut section, said cage section entrapping said metal cap and said locking ring between an upper part of said cage section and said top of said nut section.
 3. A protector for axle threads on a skateboard and a bearing of a wheel on the threaded skateboard axle as set forth in claim 2, wherein said metal cap further comprises: a crown; and a circumscribing flange; whereby a top of said cage section entraps said circumscribing flange of said metal cap between said top cage section and said locking ring.
 4. A protector for axle threads on a skateboard and a bearing of a wheel on the threaded skateboard axle as set forth in claim 1, wherein said locking ring further comprises: resilient material into which the axle threads may cut or pass.
 5. A protector for axle threads on a skateboard and a bearing of a wheel on the threaded skateboard axle as set forth in claim 1, further comprising: a shield through which the threaded skateboard axle may pass, said shield adapted to cover and protect an inside bearing of the skateboard wheel while said flange coupled to said nut section protects an outer bearing of the same skateboard wheel.
 6. A protector for skateboard axle threads on a skateboard axle having a skateboard wheel with an accompanying bearing, comprising: a nut section having a top, a bottom, and a central axis, said nut section adapted to threadably engage the skateboard axle; a flange coupled to said nut section adjacent said bottom, said flange extending outwardly from said bottom in a direction generally perpendicular to said central axis, said flange sized and adapted to cover and protect the skateboard wheel bearing present on the skateboard axle; a locking ring coupled to said nut section, said locking ring constructed of resilient material into which threads of the skateboard axle may cut or pass, said locking ring serving to retain itself and said nut section upon the skateboard axle; a metal cap coupled to said locking ring, said metal cap having a crown and a circumscribing flange; and a cage section coupled to said top of said nut section, said cage section entrapping said metal cap and said locking ring between an upper part of said cage section and said top of said nut section, said cage section entrapping said circumscribing flange of said metal cap between said top cage section and said locking ring; whereby a threaded skateboard axle of a skateboard truck is protected from abrasion by said metal cap and a bearing of wheel upon said threaded axle is protected from debris by said flange.
 7. A protector for skateboard axle threads on a skateboard axle having a skateboard wheel with an accompanying bearing as set forth in claim 6, further comprising: a shield through which the skateboard axle may pass, said shield adapted to cover and protect an inside bearing of the skateboard wheel while said flange coupled to said nut section protects an outer bearing of the same skateboard wheel.
 8. A skateboard truck, comprising: A threaded axle; A skateboard wheel having a first bearing rotating upon said threaded axle; a nut section having a top, a bottom, and a central axis, said nut section adapted to threadably engage said threaded axle; a flange coupled to said nut section adjacent said bottom, said flange extending outwardly from said bottom in a direction generally perpendicular to said central axis, said flange sized and adapted to cover and protect said first bearing; a locking ring coupled to said nut section; and a metal cap coupled to said locking ring; whereby said threaded axle of a skateboard truck is protected from abrasion by said metal cap and said first bearing of said skateboard wheel is protected from debris by said flange.
 9. A skateboard truck as set forth in claim 8, further comprising: a cage section coupled to said top of said nut section, said cage section entrapping said metal cap and said locking ring between an upper part of said cage section and said top of said nut section.
 10. A skateboard truck as set forth in claim 9, wherein said metal cap further comprises: a crown; and a circumscribing flange; whereby a top of said cage section entraps said circumscribing flange of said metal cap between said top cage section and said locking ring.
 11. A skateboard truck as set forth in claim 8, wherein said locking ring further comprises: resilient material into which threads of said threaded axle may cut or pass.
 12. A skateboard truck as set forth in claim 8, further comprising: a shield through which said threaded axle passes, said shield adapted to cover and protect an inside of a second bearing of said skateboard wheel while said flange coupled to said nut section protects an outside of said first bearing of the same skateboard wheel.
 13. A skateboard truck as set forth in claim 12, further comprising: said first and second bearing being the same bearing.
 14. A skateboard truck, comprising: A threaded axle; A skateboard wheel having a first bearing rotating upon said threaded axle; a nut section having a top, a bottom, and a central axis, said nut section adapted to threadably engage said threaded axle; a flange coupled to said nut section adjacent said bottom, said flange extending outwardly from said bottom in a direction generally perpendicular to said central axis, said flange sized and adapted to cover and protect said first bearing; a locking ring coupled to said nut section, said locking ring constructed of resilient material into which threads of said threaded axle may cut or pass, said locking ring serving to retain itself and said nut section upon said threaded axle; a metal cap coupled to said locking ring, said metal cap having a crown and a circumscribing flange; and a cage section coupled to said top of said nut section, said cage section entrapping said metal cap and said locking ring between an upper part of said cage section and said top of said nut section, said cage section entrapping said circumscribing flange of said metal cap between said top cage section and said locking ring; whereby said threaded axle of a skateboard truck is protected from abrasion by said metal cap and said first bearing of said skateboard wheel is protected from debris by said flange.
 15. A skateboard truck as set forth in claim 14, further comprising: a shield through which said threaded axle passes, said shield adapted to cover and protect an inside of a second bearing of said skateboard wheel while said flange coupled to said nut section protects an outside of said first bearing of the same skateboard wheel.
 16. A skateboard truck as set forth in claim 15, further comprising: said first and second bearing being the same bearing. 